Inflatable airbag systems for use in transportation vehicles are well known. In such systems, a cushion of fabric or the like is typically inflated by a gas generating element when a sensor measures deceleration at a level corresponding to a crash event. Prior to activation, the cushion is typically stored in a bin-like housing which may be molded from a suitable polymeric material such as glass-filled Nylon (i.e. polyamide) or the like. By way of example only, and not limitation, one such known material for use in forming airbag housings is a composite of Nylon 6 (also known as PA-6) with about 40% glass having a thickness of about 3 mm. Of course, other construction materials, fillers and thicknesses are also used
While known prior housings may be fully functional, such housings are typically designed with additional thickness and/or stiffening ribs or other features to promote integrity over a wide range of operating conditions. In particular, such additional thickness or other strengthening features may be incorporated to promote integrity at low temperature conditions. In this regard, low temperature conditions may cause some degree of embrittlement in various molded polymeric materials. The practice of increasing thickness and/or including strengthening features is used to ensure that any embrittlement that may occur will not lead to a loss of integrity when the housing is subjected to the forces associated with airbag deployment at low temperature.
The practice of using additional thickness and/or including molded-in ribs or other strengthening features in airbag housings is generally successful in overcoming any issues associated with embrittlement. However, designing in significant additional thickness and/or other strengthening features may result in added complexity or cost during the manufacturing process. Moreover, such added materials will necessarily increase the weight of the housing. Increased weight is generally considered to be undesirable in transportation vehicles due to corresponding additional fuel consumption requirements. Accordingly, an airbag housing which maintains its integrity at low temperature conditions with reduced thickness requirements would represent a significant advancement over the known art.